Noncurrent Deferred Tax Assets Recorded in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Equity [Abstract]
Balance at beginning of period, Pension and Postretirement Benefit Plans	$ 66,467	$ 68,568
Other comprehensive earnings, tax effect, Pension and Postretirement Benefit Plans	(944)	(1,016)
Balance at end of period, Pension and Postretirement Benefit Plans	65,523	67,552
Balance at beginning of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	1,290	1,799
Other comprehensive earnings, tax effect, Unamortized Value of Terminated Forward Starting Interest Rate Swap	(131)	(120)
Balance at end of period, Unamortized Value of Terminated Forward Starting Interest Rate Swap	1,159	1,679
Balance at beginning of period, Net Non current Deferred Tax Assets	67,757	70,367
Other comprehensive earnings, tax effect, Net Non current Deferred Tax Assets	(1,075)	(1,136)
Balance at end of period, Net Non current Deferred Tax Assets	$ 66,682	$ 69,231